php geolocation listing website enhacements

I have a php script wich I need some changes. It's a geolocated listing platform. Example: real state or classifieds displayed as points on google maps. Needs to have good experience with google maps api. In short description, the changes that need involve: 1) ESC or click away closes description windows 2) button that will hide all markers (leaving only the map, in case a lot of markers are overlaying some needed information on the map) 3) When adding listing, determine the Latitude and Longitude when adding a listing, instead of clicking the map 4) Remove pages from results, make the results appear with ajax, as scrolls down That's it!